My recent project, TrackWarcraft.com, provides a quick way to evaluate the gear and experience for people you're considering inviting to your group. With the Track Warcraft add-on you can instantly look up information about every character in the LFG channel and pick the best characters.

The add-on is a pure Warcraft Lua add-on with no executables, so it's 100% safe. A how-to instruction guide for the add-on with screenshots and examples is on the trackwarcraft blog here.

TrackWarcraft also provides a feed of a character's achievements, new levels, and gear upgrades. You can add this feed to your favorite feed reader, such as Google Reader, and be notified whenever a character completes an achievement or upgrades their gear.